Recently, the image quality of liquid crystal television is enhanced. A liquid crystal display with the four-primary-color system is proposed in which a liquid crystal panel is improved from three-primary-color version to four-primary-color version in order to expand the gamut (e.g., Japanese Patent No. 4034022). For example, when red, green, blue and yellow are selected as the four primary colors, it is possible to expand the gamut for yellow or cyan in the liquid crystal panel. When yellow is added as the primary color, it is possible to expand the gamut for green and thus to expand the gamut for cyan which is the complementary color for green and blue.